Jeff J Mitchell/Getty Images(MOSCOW) -- Amidst accusations of piracy, activists have been detained in Russia and the U.S. State Department confirmed on Wednesday that an American citizen is among those charged with piracy related to a Greenpeace protest.

American Dmitri Litvinov was among five activists charged with piracy by Russian prosecutors. A second American citizen, the captain of the ship, has not been charged, says State Department spokeswoman Marie Harf, though he remains in a Russian prison.

About 30 activists and one journalist were aboard a Greenpeace International ship in the Arctic Ocean when the ship was seized by Russian border guards on September 20, reports the New York Times. Earlier, members of the crew had attempted to use inflatable boats to board a Russian offshore oil platform and were doused with cold water and threatened by security.

The piracy charges carry a maximum sentence of 15 years in prison.

Harf also said that the U.S. consulate in St. Petersburg had met with the two detained American citizens.